Antistatic nonhalation motion picture film



May 9, 1933. D. M MASTER 1,908,527

ANTISTATIC NONHALATION MOTION PICTURE FILM Filed July 7, 1931 Donald IIZcTIZasZer,

after 04 ZOb Patented May 9, 1933 UNITED STATES PATENT OFFICE DONALD MCM'ASTER, OF ROCHESTER, NEW YORK, ASSIGNOR TO EASTMAN KODAK COM- PANY, OF ROCHESTER, NEW YORK, A. CORPORATION OF NEW YORK' ANTISTATIC N ONKALATION MOTION PICTURE FILM Application filed July 7,

This invention relates to photographic film and more particularly to motion picture film for use as a negative material for studio purposes where the illumination is largely from light sources, such as incandescent electric bulbs, the light from which is especially poor in the blue and ultra-violet and where provision is especially desirable against static and halation.

There are particular advantages in the use of a permanent dye for anti-halation purposes, since the removal, bleaching and destruction of the dye frequently has deleterious effects in the continuous processing of motion picture film.

When necessary, reference will be made to the single figure of the accompanying drawing in which there is shown on a greatly magnified scale, a section of the film emdying my invention. In the preferred form of my invention, I utilize a film support or base 1 of a nitrocellulose composition of the type now in general use, there being upon one surface a photographically sensitive layer 2 which is panchromatic or specially sensitive in the red and yellow portions of thespectrum. There is applied directly to the support 1 a dye layer 3 by means of suitable solvents which penetrate the support. It sometimes happens that there is a tendency for particles of dye to flake oil and there is also a very strong and objectionable tendency for film of nitrocellulose com osition to create static as it passes throug the camera. I overcome both of these difiiculties by applying directly over the dye layer a cellulose acetate varnish which remains in the form of a very thin layer. The particular composition of the nitrocellulose support and the varnish layer are not material to the invention since these are well known.

I contemplate the use of other materials for the support and for the varnish, it being only necessary that they shall have opposite 1931. Serial No. 549,167.

found that halation is sufliciently prevented 1 if the density throughout the visual range is of the order of .20 to .25, although I do not limit myself to these Particularly in the blue'region of the spectrum, it may well fall considerably below that figure, say to .10. Preferably, however the density should not be greater than .30. A layer of this type sufiiciently prevents halation and permits of printing in the regular machines without too greatly retarding that operation. If the tint is neutral and of the specified density, the qualityof the picture may be judged by ordinary standards.

The particular dyes that may be used are not essential to the invention, though I have found Nigrosine to be satisfactory. However, mixtures of dyes may be used, such, for instance, as Spirit blue R and Al hazurene or a mixture of Zapon black, Metanil yellow and Toluidine blue. These dyes would, of course, be mixed in such proportlon as to give the desired non-color-selective appearance.

I contemplate as included within my invention, all such modifications and equivalents as fall within the reasonable scope of the appended claim.

Having thus described my invention, what I claim as new and desire to be secured by Letters Patent of the United States is:

I Motion picture film comprising a support of a cellulose nitrate composition, having on one surface a photographic emulsion highly day of June 1931.

sensitive to red and yellow light and, applied directly on the other surface, a permanent dye layer having a density between .10 and .30 as to H ht of all visible wave lengths and, ap- 5 pli directlypver said (1 e layer, a permanent very thin layer of a ce lulose acetate composition which acts both to prevent static and to rotect the dye layer.

igned at Rochester, New York this 30th DONALD MOMASTER. 

